Lithographic-press blanket.



No. 680,752. Patented Aug. 20, MIL H. G. BENDER. LITHOGBAPHIG PRESS BLANKET.

(Application filed Nov. 4, 18994) (No Model.)

INVENTUE' ATTES T lJNiTETi STATES PATENT @EETeE,

HORACE G. BENDER, OF AKRON, OHIO.

LlTHOGRAPHIC'PRESS BLANKET.

SPECIFICATION forming part Of Letters Patent NO. 680,752, dated August 20, 1901.

Application filed November 4. 1899. Serial No. 735,744. (No model.)

To all whom it may concern.-

Be it known that I, HORACE G. BENDER, a citizen ofthe United States,residing at Akron, in the county of Summit and State of Ohio, have invented certain new and useful Improvements in Lithographic-Press Blankets; and I do declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to the art of printing; and the object of the invention is to provide a cushioned printing-cylinder with a separate and removable surface-covering, all substantially as shown and described, and particularly pointed out in the claim.

In the first place, on lithographic machinery, whether of the vibrating or rotating character, to be used for stone or the new metal plates recently adopted, a rubber blanket of more or less elasticity or resilience is necessary upon the cylinder which receives the impression and carries the sheet to be printed, this for the purpose of overcoming the rolling out which would necessarily follow the use of solid cylinders without the intervention of the rubber blanket. As indicated by the character of the blanket, rubber is first choice as a material for blankets, and there seems to be but one objectionnamely, that the material, be it paints or inks, which might be used for printing, always more or less soils the blanket and the articles which are used in cleansing the same, such as water, oil, benzene, turpentine, 850. These are all very damaging to the rubber, deteriorating it very rapidly, and within a month or two or three at the longest the blanket becomes utterly unfit for further use. I have therefore found it expedient to devise some means of protecting these rubber blankets, and to this end have conceived the idea of a cloth covering coated with an oil, water, benzene, (50., re-

sisting material, preferably paint of a superior quality carefully and properly applied to secure the required evenness of surface and thickness and all stretched tightly over the rubber blanket referred to.

In the accompanying drawings, Figure 1 is a perspective elevation of a cylinder in which my invention is represented, and Fig. 2 is a cross-section of the cylinder and its covcrin gs as seen in Fig. 1. Fig. 3 is a detailed perspective of sections of the blanket and its cover.

' In the views thus shown, A represents what may be regarded as a common form of cylinder which I am employing for printing in colors on cloth, thus producing what is practicallylithograph-printing in so far as the product is concerned, though I do not have the lithographic stone to work from. In other words, I print from a metallic surface instead of stone, but get substantially the same effect as from stone and that on clothsuch, for example, as white muslin. In doing this work it has been found necessary to cushion the metallic cylinder, so as not to allow its smooth hard surface to run direc'tlyover or upon the sheet or body to be printed, and -for this purpose a suit-ably and specially prepared blanket or coverBisused. This blanket, so called, maybe a sixth to an eighth of an inch in thickness and of course must be uniform and even throughout, so as to do perfect work. It is preferably of rubber, so constructed as to cushion, but not yield or stretch objiectionably, and it is fastened at one edge around the angles of the cylinder over a series of short sharp-pointed teeth 2 and at the other edge is gathered around the roll O. Of course any equivalent way of stretching the blanket and of taking up its slack may be adopted. A pawl-and-ratchet mechanism 3 is shown here for engaging the roll O and holding it when adjusted.

I employ an artificial covering D for the blanket,which in use lies so closely and evenly upon the blanket that it is the same as if it were the outer surface thereof, and yet is impenetrable by the ink or acids, is separately attachable and detachable, is inexpensive primarily, so that it can be thrown away when it becomes unserviceable, and can be cleansed for more or less repeated use. This sheet of covering is secured at one edge by the pins2 and at the other edge by its own roll E and is stretched to lie perfectly close on the blanket. This it has been found to do without danger of pulling away, and its operation gives perfeet satisfaction besides working a very great economy in protecting the blanket.

Of course the invention is not limited to my own machine and use, but maybe used in regular lithographic work as well and wherever it may be found useful.

Another advantage obtained by this improvement is the purchase and use of a rubber blanket of a much thinner, and consequently cheaper, kind than formerly, because now I need it only for its cushion and not for its finished surface for the reason hereinbefore set forth, so that altogether the improvement is of very material value.

Any supplemental cover for the blanket which will give the effect, substantially, of a heavy oil-cloth cover and be impervious or impenetrable to oils and acids will serve my purpose. In other respects the cover may be or resemble oil-cloth or cotton-duck fabric, which is like table oil-cloth, except that it 1 preferably is a little heavier, and the coating whereof also resembles such oil-cloth or what i is known in the market as enamel duck,

which is a heavier grade of goods, but of the same general kind as table oil-cloth. Then as it gets worn and leaky it can be replaced with a rubber blanket Wrapped about the cylinder, and a separate cover of fabric stretched over said blanket, and coated with materials which will prevent oil, acid, and the like deleterious matter in the ink or paint in which the printing is done from reaching the rubber blanket, whereby the said blanket is protected and itslife prolonged.

Witness my hand to the foregoing specification this 17th day of October, 1899.

HORACE G. BENDER. Witnesses:

ADA HANSCOM, W. H. SPIsER. 

